There is laboratory animal data and limited epidemiological studies that suggest that BPA may have adverse effects on reproductive function in males. Animal studies indicate that BPA may affect hormone levels, sperm quality, and penile erections. Published studies of men in China with occupational exposures to BPA reported increased sexual dysfunction and diminished semen quality. NIOSH will conduct a study utilizing objective laboratory measures to assess both body burden of BPA and quantitative measures of reproductive health in men exposed to BPA in the to clarify the risk of BPA exposure. The project has undergone extensive peer review, tripartite review, and is currently under IRB review. Preparation for conducting the initial walkthroughs and onsite surveys has begun. A liquid chromatographic (LC)-UV method for analysis of BPA in air and surface samples has been developed. Multiple media were assessed for BPA recovery and methods and media have been optimized for field studies. The target analytical method, based on the anticipated improvement in specificity and sensitivity relative to the LC-UV method, is LC-mass spectrometry-mass spectrometry (MS-MS). LC-MS-MS is much more specific in its detection. Initial tests using LC-MS-MS confirmed a response for BPA, although with a weak intensity signal. Extensive exploration of the effects of solvent composition, pH, and instrumental analytical parameters will be conducted to optimize the sensitivity of the method